Lubricating device for sewing machines



Aug. 7, 1945. F. PARRY 2,381,685

LUBRICATING DEVICE FOR SEWING MACHINES Original Filed Dec. 18, 1941 2 Sheets-Sheet l w w N go Frank Parry Aug. 7, 1945. F. PARRY LUBRICATING DEVICE FOR SEWING MACHINES Original Filed Dec. 18, 1941 2 Sheets-Sheet 2 Patented Aug. 7, 1945 LUBRICATING DEVICE FOR SEWING MACHINES Frank Parry, Bridgeport, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J a corporation of New Jersey Original application December 18, 1941, Serial No.

Divided and this application August 6, 1942, Serial No. 453,779

'15 Claims. (Cl. 112-256) This invention relates to lubricating devices more particularly adapted for supplying lubricant to the thread-carrier raceway of a sewing machine rotary loop-taker.

The primary object of this invention is to pro- :vide simple means, eflective upon operation of the machine, for supplying with certainty a requisite quantity of lubricant to the thread-carrier raceway of a loop-taker.

Another object of this invention is to obviate flooding of a sewing machine loop-taker, when the machine is out of operation and is provided with a supply of lubricantdisposed above the level of the loop-taker and having conduit connections with said raceway.

Other and more specific objects of the invention will be apparent from the following description and claims.

The invention consists in the lubricant supplying and delivering devices hereinafter described in connection with the accompanying drawings, which. illustrate a. preferred embodiment of the invention and in which:

Fig. 1 is a front-side elevation of the bed mechanism and a portion of the bracket-arm of a sewing machine containing the present improvement, the work-supporting plate of the bed frame being shown in vertical section. Fig. 2 is a vertical section of the lubricant-reservoir portion of the machine bracket-arm, the section being taken substantially on the line 2-2 of Fig. 1. Fig. 3 is a substantially horizontal and slightly reduced section of the bracket-arm, the section being taken substantially on the line 3-3 of Fig. 1. Fig. 4 is a top plan view, partly in horizontal section, of the bed-frame and -mechanism of the machine, the work-supporting plate being partly broken away. Fig. 5 is a transverse vertical section of the bed-plate, the section being taken substantially on the line 5-4 ofFig. 4and illustrating the loop-taker mechanism. Fig. 6 is a detail perspective view of the closure-insert for the sleeve which houses one end of the loop-taker shaft. v

This application is a division of application Serial No. 423,429, filed December 18, 1941.

Referring to the drawings, the sewing machine has a frame including a work-supporting bedplate l0 and a bracket-arm having a hollow standard ll rising from one end of the bed-plate.

- Suitably secured upon the bed-plate I0 is the usual throat-plate 12 provided with feed-slots, as

is supported and actuated by mechanism which is fully illustrated and described in a copending patent application Serial No. 422,482, filed De-- cember 11, 1941.

The feed-dog I5 is opposed in its work-engaging movements by the usual spring-depressed presserfoot I6. Operating through the throat-plate needle-slot I4 is a vertically reciprocatory and laterally vibratoryneedle ll which may be actuated by any usual or suitable mechanism (not shown), whereby the plane of lateral vibration of the needle is transverse to the line of feed of the work.

Disposed below the bed-plate l0 and complemental to the needle l1 in the formation of zigzag lock-stitches is a loop-taker l8 of the rotary hook type having its axis of rotation extending horizontally crosswise of the bed-plate i0 and substantially parallel to the line of feed of the work, whereby the plane of rotation of the looptaker is substantially parallel to the plane of needle-vibration.

The loop-taker l8 has a body including a cylindrical side wall IS, an inner end wall 20, and a horizontally apertured hub 2|. The side wall I9 is internally provided with an annular raceway 22. Journaled in the loop-taker raceway 22 I3, and with a needle-slot H which is elongated lengthwise of the bed-plate l0. Operating through the feed-slots I3 is a feed-dog I! which is a peripheral bearing-rib 23 of a thread-carrier 24 about which the loop-taker is adapted to cast needle-thread loops in the formation of lockstitches; the bearing-rib 23 of thethread-carrier being retained in the raceway 2-2 by a gib 25 carried by the outer rim of the loop-taker side wall I9. The thread-carrier 24 is engaged by a stop-finger 26 suitably secured to the under side of the bed-plate l0 and functioning to restrain the thread-carrier against rotation with the looptaker.

The hub 2| of the loop-taker is secured by screws 21 upon one end of a short loop-taker shaft '28 disposed below the bed-plate III to extend horizontally rearwardly from the loop-taker l8. The loop-taker shaft 28 is rotatably journaled in horizontally spaced antifriction or ballbearings 29 seated in the opposite side walls of a hollow gear-casing 30 depending from the bedplate i0 and, in the present case, integral with said bed-plate.- The gear-casing 30 functions also as a lubricant-reservoir, and access to the mechanism housed within the chamber 3| "of the easing may be had by removal of an end-closure platev 32 detachably fastened by screws, as 33 to the casing.

Secured upon the loop-taker shaft 28, by a screw 3|" and between the ball-bearings 29, is a spiral pinion-gear 35. The pinion-gear 38 is engaged, within the chamber 3| of the casing 33, by a spiral driving-gear 38 carried by a rotary bed-shaft 31 disposed below and extending horizontally crosswise of the loop-taker shaft 28. The bed-shaft 31 is rotatably Journaled in a bearing bushing 38 carried by the casing 33; the end of said bed-shaft 31 which carries the driving gear 36 terminating in the chamber 3| of said casing. The bed-shaft 31 is additionally journaled in suitable bearing-lugs depending from the bed-plate l8, and the opposite end of said shaft 31 carries a pulley 39 driven by a belt 43 in timed relation whereby the bed-shaft 31 rotates once for each complete reciprocation of the needle H. The ratio of the gears 35 and 38 is preferably such that the loop-taker l8 rotates twice for each complete reciprocation of the needle.

The loop-taker shaft 28 is longitudinally provided with a substantially straight cylindrical bore 4| which is closed at the end of said shaft 28 within the hub 2| of the loop-taker and is open at the opposite end of said shaft. The shaftbore 4| is lengthwise inclined to the axis of rotation of the shaft 28 to induce movement of oil within said bore toward the loop-taker end of the shaft, upon rotation of the shaft. To this end, the bore 4| is disposed substantially concentric with the shaft 28 at the end of the shaft remote from the loop-taker and eccentric to said shaft at the opposite end thereof. The closed end portion of the shaft 28 is externally formed with a circumferential groove 42 connected with the bore 4| of the shaft by a radial shaft-aperture 43. The inner end wall 20 of the loop-taker I3 is provided with a lubricant-duct 44 connecting the circumferential groove of the loop-taker shaft 28 with a duct 45 formed in the cylindrical side wall IQ of the loop-taker to terminate in the raceway 22. The open-bore end portion of the loop-taker shaft 28 opposite the loop-taker is externally provided with a spiral thread 48 constituting a lubricant-pump and having a lead such that the thread comprises impelling means for feeding lubricant toward that end of 'the shaft; the threaded end portion of the loop-taker shaft being disposed in an opening 41 of a sleeve 48 suitably secured adjacent the ball-bearing 23 in the rear wall of the casing 33. The opening 41 of the sleeve 48 is preferably slightly larger than the diameter of the threaded portion of the looptaker shaft 28 to provide a slight clearance between the shaft and the sleeve surrounding the same.

This clearance is preferably of the order of .0025 inch and while such as to insure feeding of lubricant by the shaft-thread 48 during the operation of the machine, it is suihcient to permit drainage of lubricant past the shaft-thread when the machine is idle.

The shaft 28 terminates within the sleeve 48, and the sleeve-opening 41 is provided at its outer end with a closure-disk 43. As illustrated in Figs. 4 and of the drawings, the closure-disk 49 is partly cut away in the side face thereof adjacent the end of the loop-taker shaft 28 to form a shoulder 50 disposed at substantially the level of the inner bottom-wall of the shaft-bore 4|; the cut away face of said disk above the diskshoulder 58 being spaced slightly from the end of the shaft 28 to form a shallow lubricant clearance recess 5|, and the shouldered or lower end face of the disk 43 being disposed in contact with the end of said shaft. The sleeve 48 is provided with a vertically disposed lubricant-inlet duct 52 spiral thread 48 of the loop-taker shaft and the cylindrical wall of the sleeve-opening 41 together comprise a pump-seal for the b'y-pass 54.

Lubricant is supplied in measured quantity to the bed-plate duct 53 from a drip-feed lubricantreservoir which is built into the bracket-arm standard ll of the machine. For this purpose. the front side wall of the standard I l is inwardly and outwardly enlarged at the lower end of the standard to form a wall 55 of substantial thickness and defining a boss of which the lower portion 58, externally of the standard H, has flattened and substantially parallel outer side faces merging into an upper portion 51 of cylindrical contour.

The upper or cylindrical portion 51 of the bracket-arm boss is formed with a cylindrical cavity 58 constituting a lubricant-reservoir, and the lower portion 88 of said boss is formed with a relatively smaller cylindrical cavity 53 providing for inspection of the rate of feed of lubricant from the reservoir 58; said cavities being separated from each other by an intermediate boss-wall 83. Lubricant may be supplied to the reservoir 88 through a filling-aperture 8| provided in the bosswall 51 at the upper side thereof.

Threaded into a vertical aperture provided in the intermediate boss-wall is a valve-nipple '82 having an enlarged head 83. The valve-ni ple 82 is longitudinally provided with a shouldered vertical aperture 84 to form a lubricant-conduit.

connecting the cavities 58 and 53. The nippleconduit 84 has a downwardly constricted conical valve-seat 85, and the head 83 of the valve-nipple has a transverse aperture 88 forming a lateral lubricant-entrance duct. Extending downwardly into the valve-nipple 82 is a valve-rod 81 having a conical lower end complemental to the valve-seat 85 in controlling the flow of lubricant through the valve-nipple 82. The valve-rod 81 extends through a vertically apertured bushing 88 adjustably threaded into the boss-wall 51 in vertical alinement with the valve-nipple 82. Pivoted to the upper end of the valve-rod 81, externally of the bushing 88, is a manually operable release-lever 83; the valve-rod 81 being embraced by a coil-spring 13 bearing against the lower end of the bushing 88 and yieldingly urging the valverod downwardly into engagement with the valveseat 65 when the release-lever 83 is disengaged from the bushing 88. As is usual in needle-valves a lubricant-aperture 13 and at the upper side thereof with a vent-aperture 14. The outer face of the disk 12 is preferably provided with a white coating to form a contrasting back-ground visibly indicating the oil-level in the reservoir 58. Disposed in the lower cavity 69 of the bracketarm boss is an outwardly open cylindrical liner l8 having'an inner end wall 15'. The cylindrical wall of the liner I6 is provided with a valve-nipple clearance-aperture and with a diametrically opposite discharge-aperture 16. The inner face of the liner I and particularly the end wall 75' thereof is also preferably coated white.

The boss-cavities I8 and 88 are provided with window-closures at the outer side of the bracketarm standard II. To this end, a sheet ll of transparent'material, such as Lucite or the like and preferably having a contour corresponding to 1 the external peripheral shape of the boss 58, I1 is secured to the outer face of said boss. .A sheetmetal cover-plate I8 is secured against the transparent sheet II by screws I8 passing through said sheet and threaded into the boss 56, 51; a sealing gasket 80 being preferably interposed between the sheet 11 and the boss 56, 51. The cover-plate 18 has a circular window-opening 8| corresponding to the diameter of the upper bosscavity or reservoir 58 and a smaller windowopening 82 corresponding substantially to the diameter of the lower or feed-inspection cavity 59. The transparent sheet or gauge-plate Zll is spaced from and disposed substantially parallel to the disk 12, to provide clearance therebetween for lubricant passing through the disk-aperture '3.

Threaded into the bottom wall of the cavity 58 is an attaching nipple-83 having a shouldered vertical aperture-84 internally threaded to receive a securing-nut 85 for one end of a tubular conduit 86; said securing-nut 85 extending downreservoir and lubricant-feed inspection cavities obviates the employment of extraneous and unsightly oil-cup devices. The present improvement provides for convenient inspection of the lubricant-supply and the rate of lubricant-feed therefrom, and has a relatively low manufacturing cost.

From the foregoing description it will be understood that the conduit 06, the bed-plate duct 58, the sleeve-duct 52, the sleeve-opening 41, the clearance-recess ii, the loop-taker shaft bore ll, the shaft-aperture 43 and the loop-taker ducts l4 and 45 together comprise lubricant-conducting connections between the drip-feed lubricant reservoir and the loop-taker raceway 22. The bypass comprises a side outlet for the lubricant supplied through the described connections.

Should the operator fail to shut off the feeding of lubricant from the reservoir 58, when the machine is idle, the lubricant supplied gravitationally to the sleeve-duct 52 will flow to the bottom of the sleeve-opening l1 and will drain past the shaft-thread 46 and into the reservoir 3i through the lubricant by-pass provided by the recess 54 between the sleeve 48 and the adjacent antifriction bearing 29 which is open at the opposite side thereof to the reservoir 3|. This construction consequently obviates flooding of the loop-taker raceway when the machine is idle and insures that lubricant is supplied to one of the ball-bear lugs 29 and through said bearing to the teeth 6 thread 48 into the clearance recess St; the closure-disk shoulder 50 directing the lubricant into the shaft-bore M. The shaft-thread 48 has a small lead to feed the lubricant slowly, whereby the lubricant enters the shaft-bore by flow action.

The inclined shaft bore 4| then delivers the lubricant to the loop-taker connections with the thread-carrier raceway 22. The ball-bearing 29 adjacent the loop-taker I8 is supplied with lubricant dispersed within the casing 3l by the driven l5 gear 86.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine a rotary shaft having a longitudinal bore open at one end of said shaft,

a loop-taker carried by the opposite end of said shaft and provided with a thread-carrier, raceway having lubricant-conducting connections with said shaft bore, lubricant-impelling means carried by the open-bore end of said shaft externally of the shaft, a sleeve surrounding said lubricant-impelling means of the shaft in spaced relation thereto and having a lubricant-inlet duct terminating in the shaft opening of the sleeve, an end-closure for said sleeve disposed in engage- 80 ment with the adjacent end of said shaft and provided in its face proximate to said shaft with a lubricant-clearance recess leading to said bore of the shaft, and means for supplying lubricant to the duct of said sleeve.

, 35, 2 In a sewing machine, a horizontally disposed rotary shaft having a longitudinal bore open at one end of said shaft, 9. loop-taker carried by the opposite end of said shaft and provided with a thread-carrier raceway having lubricant-conducting connections with said shaft bore, lubricant-impelling means carried by the open-bore end of said shaft externally of the shaft, a sleeve ,surrounding said lubricantimpelling means of the shaft and having ajlubricant-inlet duct terminating in the shaft opening of the sleeve, a closure-disk disposed in said sleeve and having a recess in its face proximate to the open-bore end of said shaft,-said recess providing a shoulder disposed substantially at the level of the lower wall of said shaft bore, and said recess also providing a lubricant-clearance space between said disk and the upper wall of said shaft-bore, and means for supplying lubricant to the duct of said sleeve.

3. In a sewing machine having a frame includg a work-support, a. casing disposed below said work-support and provided with a lubricant-reservoir, a horizontally disposed rotary shaft having a longitudinal bore open atone end of said shaft and provided with a thread-carrier racewayv having lubricant-conducting connections with said shaft bore, said shaft being externally provided at the open-bore end portion thereof with a spiral thread having a lead to feed lubricanttoward said open-bore end of the shaft, an

antifriction-bearing for said shaft disposed in said casing adjacent said spiral thread, a sleeve surrounding the threaded portion of said shaft in spaced relation thereto and having a lubricant inlet-port adjacent said thread, an end-closure and means for supplying lubricant to the duct of of the driving gear 88 which is disposed under said sleeve, said sleeve and antifriction bearing providing therebetween a lubricant by-pass open to said reservoir. I

4. In a sewing machine, a rotary loop-taker having a thread-carrier raceway, a thread-oarrier journaled in said raceway and restrained against rotation with said loop-taker, a drip-feed lubricant supply reservoir disposed above the level of said loop-taker, lubricant-conducting connections with said reservoir for supplying lubricant to said raceway, said connections including a lubricant by-pass effective when the machine is out of operation to divert lubricant from delivery to said raceway, and means carried by an operating part of the machine for functionally closing said by-pass.

5. In a sewing machine, a rotary loop-taker having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a lubricant supply reservoir disposed above the level of said looptaker, lubricant conducting connections with said reservoir for supplying lubricant to said raceway, said connections including a lubricant bypass outlet effective when the machine is out of operation to divert lubricant from delivery to said raceway, and lubricant-feeding means automatically rendered effective upon operation of the machine for feeding the lubricant past said outlet.

6. In a sewing machine, a rotary loop-taker having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a drip-feed lubricant supply reservoir disposed above the level of said loop-taker, lubricant conducting connections with said reservoir for supplying lubricant to said raceway, said connections including a lubricant by-pass effective when the machine is out of operation to divert lubricant from delivery to said raceway, and lubricant pumping means for rendering said by-pass ineffective during the operation of the machine.

'7. In a sewing machine, a rotary shaft having a longitudinal bore, a loop-taker carried by said shaft and having a thread-carrier raceway, a lubricant-supply reservoir disposed above the level of said loop-taker, lubricant-conducting connections including said shaft bore between said reservoir and said raceway, said connections having a by-pass for diverting lubricant from delivery to said raceway when the machine is out of operation, and means carried by said rotary shaft for functionally closing said by-pass during the operation of the machine.

8. In a sewing machine, a rotary shaft having a longitudinal bore, a loop-taker carried by said shaft and having a thread-carrier raceway, a lubricant-supply reservoir disposed above the level of said loop-taker, lubricant-conducting connections including said shaft-bore between said reservoir and said raceway, said connections having a lubricant by-pass outlet effective to divert lubricant from delivery into said shaft bore when the machine is out of operation, and a pump-seal for said by-pass outlet actuated by a moving part of the machine.

9. In a sewing machine, in combination, a rotary shaft provided longitudinally thereof with a bore open at one end of said shaft, said bore having the wall thereof inclined from the open end of the bore in a direction away from the axis of rotation of the shaft, a loop-taker carried by the end of said shaft opposite the open bore end thereof, said loop-taker havin a threadcarrier raceway, a lubricant-supply reservoir disposed above the level of said loop-taker, conduit means leading from said reservoir to the open end of said shaft bore, said conduit means having a lubricant-outlet leading away from said shaft bore, means automatically rendered effective upon operation of the machine 'for functionally closing said outlet, and lubricant-conducting connections between said shaft bore and said raceway.

10. In a sewing machine, in combination, a rotary loop-taker shaft provided longitudinally thereof with a bore open at one end of said shaft, said bore having the wall thereof inclined from the open end of the bore in a direction away from the axis of rotation of the shaft, 8. looptaker carried by the end of said shaft opposite the open bore end thereof, said loop-taker having a thread-carrier raceway, a member complemental to said shaft in feeding lubricant to the open end of the inclined bore of said shaft, one of said elements comprising said shaft and said member having a spiral lubricant-feeding thread, means comprising a drip-feed lubricant-reservoir and conduit connections therewith for supplying lubricant to said thread, and lubricantconducting connections between said bore of the loop-taker shaft and said raceway.

11. In a sewing machine, in combination, a rotary loop-taker shaft provided longitudinally thereof with a bore open at one end of said shaft, 9. loop-taker carried by the end of said shaft opposite the open bore end thereof, said loop-taker having a thread-carrier raceway, a sleeve surrounding said shaft and having lubricant-conducting connections with the open end of said bore, said sleeve additionally having a lubricant by-pass outlet leading away from said bore, a spiral lubricant-feeding thread carried by one of the elements comprising said shaft and said sleeve, said thread having a lead to feed lubricant away from said outlet and toward said bore upon operation of the machine, a lubricant supply reservoir disposed above the level of said loop-taker, a lubricant-conduit connecting said reservoir and said sleeve, and lubricant-conducting connections between the bore of said shaft and said raceway.

12. In a sewing machine, a rotary shaft provided longitudinally thereof with a substantially straight cylindrical bore inclined to the axis of rotation and open at one end of said shaft, a loop-taker carried by the other end of said shaft and having a thread-carrier raceway, lubricantconducting connections between the bore of said shaft and said raceway, said bore being disposed eccentric to said axis at the loop-taker end of the shaft and said bore having the opposite open end thereof substantially concentric with said shaft, a drip-feed lubricant-supply reservoir disposed above the level of said loop-taker, lubricant-conduit means connecting said reservoir and the end of said bore remote from the loop-taker, said lubricant-conduit means having a lubricant bypass outlet, and lubricant-feeding means automatically rendered effective upon operation of the machine for feeding lubricant through said lubricant-conduit means in a direction away from said outlet.

13. In a sewing machine, in combination, a. rotary loop-taker having a thread-carrier raceway. a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a manually regulatable lubricant supply reservoir disposed above the level of said loop-taker, lubricant-conducting connections between said reservoir and said raceway, said connections being provided with a lubricant outlet disposed to by pass the lubricant from delivery tosaid raceway when the machine is out ofoperation, and autov matically acting .means rendered effective upon operation of the machine for functionally closing said outlet.

14. In a sewing machine, a rotary shaft, a rotary loop-taker carried by said shaft and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a bearing for said shaft, a lubricant supply reservoir disposed above the level or said loop-taker, lubricant conducting connections with said reservoir for supplying lubricant to said raceway, said connections including a lubricant outlet leading to said bearing, and lubricant pumping means automatically rendered eflective upon operation of the machine for curbing the flow of lubricant through said outlet to said bearing.

15. In a sewing machine, a rotary shaft, a rotary loop-taker carried by said shaft and having a thread-carrier raceway, a thread-carrier journaled in said raceway and restrained against rotation with said loop-taker, a bearing for said shaft, means for rotating said shaft including a gear-member disposed below said bearing, a lubricant-supply reservoir, lubricant-conducting connections with said reservoir for supplying lubricant to said raceway, said connections including a lubricant-outlet disposed to direct lubricant through said bearing and upon said gear-member, and pump means carried by said shaft for functionally closing said lubricant-outlet during the operation of the machine.

FRANK PARRY. 

